Why Evil?
The Epicurean paradox points out the contradiction between the existence of evil in the world and the supposed existence of a god who is omniscient (all-knowing), omnipotent (all-powerful), omnibenevolent (all-loving), and omnipresent (present everywhere).

“Is God willing to prevent evil, but not able? Then he is not omnipotent.
Is he able, but not willing? Then he is malevolent.
Is he both able and willing? Then whence cometh evil?
Is he neither able nor willing? Then why call him God?”

― Epicurus